The present invention relates generally to automatic milking of animals. More particularly the invention relates to an arrangement for attaching teat cups to the teats of an animal as disclosed below.
The technical solutions for automatic milk extraction are becoming increasingly efficient and sophisticated. For example, today's milking robots allow a completely automatic milking procedure. Among other things, such a procedure involves automatic attachment of the teat cups. The prior art includes various examples of solutions for enabling and effecting this step.
EP 1 211 928 discloses a solution wherein the teat tip positions are estimated by means of light sources and image capturing means. The teat cups are then attached in response to the position estimates.
US-2007/0215052 discloses a teat location system for automatic milking installations. The system includes a light projection source and a camera capable of returning time-of-flight (TOF) information along with intensity information in two dimensions. Thus, three-dimensional data can be generated which represents imaged teats. Based thereon the teat cups can be attached in a relatively straightforward manner.
WO 2005/122753 reveals a gripper device capable of gripping and simultaneously holding two or more teat cups. By employing such a gripper device the average number of movements between the teat cup magazine and the animal's udder can be reduced, and thus the total attachment time can be shortened.
EP 1 100 314 shows a milking apparatus having a movable arm for moving teat cups towards the animal to be milked. Here, while being moved by the arm, the teat entrance end of at least one teat cup is located at a different level than the teat entrance end of a further one of the teat cups. Hence, the teat cups can be attached in a simple and reliable manner. Reattachment of any inadvertently detached teat cups is also facilitated thereby.
Although the above solutions may each have its specific qualities and advantages, there is still room to further improve the automatic attachment of teat cups. For example, as indicated above, for time efficiency it is desirable to reduce the number of times the robotic arm must move between the teat cup magazine and the udder. Therefore, grippers capable of carrying multiple teat cups are generally attractive. However, the anatomic characteristics of the udder and/or the teats may be such that if two or more teat cups are moved towards the udder in a multi-teat cup gripper, subsequent individual attachment of the teat cups is problematic because in this process the positioning means' view of the teats becomes obstructed and/or the udder and/or at least one teat interferes with the movement of the robotic arm carrying the gripper, the gripper and/or any other object mounted on the arm (e.g. an imaging means). Therefore, multi-grippers may be difficult/inefficient to employ, and sometimes even be excluded. It is also desirable to avoid the complex structure of a multi-teat cup carrier wherein the level of each teat cup is individually controllable. Moreover, the manner in which single-teat cup grippers are employed for teat cup attachment is sometimes sub-optimal from an efficiency point-of-view.